Wall segment for a combustion area, and a combustion area

ABSTRACT

A wall segment is for a combustion area to which a hot fluid can be applied. The wall segment includes a metallic supporting structure, with a heat protection element mounted on it. The metallic supporting structure is provided at least in places with a thin and/or metallic, heat-resistant separating layer. The separating layer is fitted between the metallic supporting structure and the heat protection element.

[0001] The invention relates to a wall segment for a combustion area towhich a hot fluid can be applied, in particular for a combustion chamberin a gas turbine. The invention also relates to a combustion area.

[0002] A thermally highly stressed combustion area, such as a furnace, ahot-gas channel or a combustion chamber in a gas turbine, in which a hotfluid is produced and/or carried, is provided with a lining forprotection against excessive thermal stress. The lining is composed ofheat-resistant material and protects a wall of the combustion areaagainst direct contact with the hot fluid, and the severe thermal stressassociated with this.

[0003] U.S. Pat. No. 4,840,131 relates to improved attachment of ceramiclining elements to a wall of a furnace. A rail system, which is attachedto the wall and has a number of ceramic rail elements by means of whichthe lining elements are held is provided in this document. Furtherceramic layers may be provided between a lining element and the wall ofthe furnace, including a layer composed of loose, partially compressedceramic fibers, which layer has at least the same thickness as theceramic lining elements, or a greater thickness. The lining elements inthis case have a rectangular shape with a planar surface and arecomposed of a heat-insulating, fire-resistant ceramic fiber material.

[0004] U.S. Pat. No. 4,835,831 likewise relates to the fitting of afire-resistant lining on a wall of a furnace, in particular a verticalwall. A layer composed of glass, ceramic or mineral fibers is fitted tothe metallic wall of the furnace. This layer is attached to the wall bymetallic brackets or by adhesive. A wire mesh network with honeycombmeshes is fitted to this layer. The mesh network is likewise used toprotect the layer composed of ceramic fibers from falling off. Acontinuous, closed surface composed of fire-resistant material isapplied to the layer secured in this way, by means of a suitablespraying method. The described method largely avoids fire-resistantparticles produced during the spraying process from being thrown back,as would be the case if the fire-resistant particles were sprayeddirectly onto the metallic wall.

[0005] A lining for walls of highly stressed combustion areas isdescribed in EP 0 724 116 A2. The lining comprises wall elementscomposed of high-temperature-resistant structural ceramic, such assilicon carbide (SiC) or silicon nitride (Si₃N₄), which are mechanicallyattached by means of a fastening bolt to a metallic supporting structure(wall) of the combustion chamber. A thick insulation layer is providedbetween the wall element and the wall of the combustion area, so thatthe wall element is at a distance from the wall of the combustionchamber. The insulation layer, which is three times as thick as the wallelement, is composed of ceramic fiber material, which is prefabricatedin blocks. The dimensions and the external shape of the heat protectionsegments can be matched to the geometry of the area to be lined.

[0006] Another type of lining for a thermally highly stressed combustionarea is specified in EP 0 419 487 B1. The lining is composed of heatprotection segments, which are held mechanically on a metallic wall ofthe combustion area. The heat protection segments touch the metallicwall directly. In order to avoid excessive heating of the wall, forexample by direct heat transfer from the heat protection segment or bythe ingress of hot active fluid into the gaps formed by mutuallyadjacent heat protection segments, the area formed by the wall of thecombustion area and the heat protection segment has cooling air,so-called sealing air, applied to it. The sealing air prevents the hotactive fluid from penetrating as far as the wall, and at the same timecools the wall and the heat protection segment.

[0007] The object of the invention is to specify a wall segment for acombustion area, in particular a combustion chamber in a gas turbine, towhich a hot fluid can be applied. A further object is to specify aheat-resistant combustion area.

[0008] The object relating to a wall segment is achieved according tothe invention by a wall segment for a combustion area, to which a hotfluid can be applied, having a metallic supporting structure and havinga heat protection element which is mounted on the metallic supportingstructure, in which the metallic supporting structure is provided atleast in places with a thin, heat-resistant separating layer, with theseparating layer being fitted between the metallic supporting structureand the heat protection element. Alternatively or additionally, theobject is achieved by a wall segment in which, according to theinvention, a metallic, heat-resistant separating layer is fitted atleast in places between the supporting structure and the heat protectionelement. The metallic separating layer may be thin.

[0009] The invention is based on the knowledge that the heat protectionsegment and the wall of a combustion area are composed predominantly ofrelatively inelastic materials such as structural ceramic and metal. Adisadvantage of a lining designed in such a way for a combustion area isthat the heat protection elements directly touch the wall of thecombustion area. For production reasons and owing to the differentthermal expansion of the wall and the heat protection element, the heatprotection element may not always be able to lie flat on the wall. Inconsequence, high forces may be produced locally at the contact points.If the heat protection element and the wall have different thermalexpansion characteristics, it is possible in unfavorable conditions forthe heat protection segments and/or the wall to be damaged due to theintroduction of high forces at the contact points when the operatingstate of the combustion area changes, for example in the event of a loadchange in a gas-turbine system. In consequence, gaps between the heatprotection element and the wall may be formed between the contact pointsof the heat protection element and the wall, where there is no contact.These gaps form access channels for hot fluid. In order to prevent theingress of hot fluid, an increased amount of sealing air would berequired in this situation between the wall and the heat protectionelement.

[0010] The refinement of a wall segment according to the invention hasthe advantage that a deformable separating layer inserted between themetallic supporting structure and the heat protection element can absorband compensate for possible relative movements of the heat protectionelement and of the supporting structure. Such relative movements can becaused, for example, in the combustion chamber of a gas turbine, inparticular an annular combustion chamber, by the materials used havingdifferent thermal expansion characteristics or by pulsations in thecombustion area, which can occur in the event of irregular combustion toproduce the hot active fluid or as a result of resonance effects. At thesame time, the separating layer results in the relatively inelastic heatprotection element lying flatter on the separating layer and on themetallic supporting structure overall, since the heat protection elementpenetrates into the separating layer in places. The separating layer canthus also compensate for irregularities, due to production effects, onthe supporting structure and/or on the heat protection element, whichcan lead to disadvantageous introduction of forces at specific points,locally.

[0011] The heat-resistant separating layer inserted between the heatprotection element and the metallic supporting structure canadvantageously be deformed elastically and/or plastically by the heatprotection element. The heat protection element can thus penetrate intothe heat-resistant separating layer in places, and deform it, andcompensate for irregularities in the contact surface of the heatprotection element and/or of the supporting structure due to productioneffects and/or occurring as a result of operation of the system. Forcescan thus be introduced over a larger area to the largely inelastic heatprotection element, overall, and the risk of damage to the heatprotection element and/or to the metallic supporting structure is lessthan when forces are introduced via the direct contact, which occurs atspecific points at least in places, between the heat protection elementand the supporting structure. The deformation of the separating layer inplaces by the heat protection element also leads to a reduction in thegap openings between the heat protection element and the separatinglayer, which reduces the flow of hot fluid behind the heat protectionelement. In order to avoid, or at least reduce, the flow behind the heatprotection elements, sealing air can be applied to a cavity formed bythe heat protection element and the metallic supporting structure. Therequirement for sealing air is decreased by reducing the gap openingsand reducing the size of the cavity volume by means of the separatinglayer.

[0012] The separating layer preferably has a thickness which is lessthan the height of the heat protection element. The expression height ofthe heat protection element in this case means the extent of the heatprotection element in the direction at right angles to the surface ofthe metallic supporting structure. The height may in this casecorrespond directly to the layer thickness of the heat protectionelement. In the case of a domed, curved or cap-shaped heat protectionelement, the height is, in contrast, greater than the wall thickness ofthe heat protection element. The separating layer may have a layerthickness of up to a few millimeters. The layer thickness is preferablyless than one millimeter, in particular up to a few tenths of amillimeter.

[0013] The heat-resistant separating layer preferably comprises a metalgrid with honeycomb cells, which grid can be deformed by the heatprotection element. The honeycomb cells of the metal grid areadvantageously filled with a deformable filling material. The honeycombcells may be produced from thin metal sheets, with a thickness of only afew tenths of a millimeter, for example from a nickel-based alloy. Thefilling material is preferably in the form of powder and is formed froma metal and/or a ceramic. The ceramic powders can be heated andtransported in a plasma jet (atmospheric plasma spray) . Depending onthe nature of the powder and the spraying condition, a layer produced bythe powder can be formed with a greater or lesser number of pores. Thehoneycomb cells are preferably filled with a porous layer, which canthus be deformed easily and provides good insulation. A metallic fillingmaterial is preferably formed from a heat-resistant alloy as is alsoused, for example, for coating gas turbine blades. A metallic fillingmaterial is formed, in particular, from a base alloy of the MCrAlY type,in which case M may be nickel, cobalt or iron, Cr chromium, Al aluminumand Y yttrium or some other reactive rare-earth element. During thedeformation and penetration of the heat protection element into theseparating layer, the deformable filling material closes the gapopenings which exist between the contact surfaces, or reduces theirsize, which leads to a reduction in the requirement for sealing air.Furthermore, the separating layer reduces the volume of the cavityformed by the heat protection element and the supporting structure, as aresult of which the requirement for sealing air is further reduced. In agas turbine, the active fluid can furthermore be cooled by the coolersealing air when said sealing air enters the combustion area, which canlead to a reduction in the overall efficiency of a gas turbine systembeing operated using the hot active fluid. The reduced requirement forsealing air in this case also leads to less reduction in overallefficiency than would be the case in a gas turbine system with heatprotection elements but without a separating layer.

[0014] The heat-resistant separating layer may also advantageouslycomprise a felt composed of thin metal wires. Such a metal felt may alsobe laid on contours having very small radii of curvature, and is thusparticularly suitable as a separating layer for a supporting structurewith an irregular shape in a combustion area, for example a metallicsupporting structure for holding heat protection elements, to whichsealing air is applied, in the combustion chamber of a gas turbine. Thethickness of the metal felt is chosen such that even relatively largegap openings between two contact surfaces of a heat protection elementand the supporting structure can be closed, or at least greatly reducedin size, by the metal felt. It is thus possible to use a wall segmentdesigned in such a way even in systems in which the amount of sealingair available is limited.

[0015] If the gap openings which result between the metallic supportingstructure and the associated heat protection elements are relativelysmall and uniform, then the heat-resistant separating layer ispreferably applied as a thin coating to the metallic supportingstructure.

[0016] In order to make it possible to withstand the loads resultingfrom the ingress of hot fluid and to protect the metallic supportingstructure effectively, the heat-resistant separating layer installedbetween the supporting structure and the heat protection element isdesigned to be scale-resistant at a temperature of more than 500° C., inparticular up to approximately 800° C.

[0017] The heat protection element is advantageously mechanicallyconnected to the metallic supporting structure of the combustion area.The contact force which the mechanical retention exerts on the heatprotection element in the direction of the supporting structure, andthus the penetration depth of the heat protection element and thedeformation of the heat-resistant separating layer, can be adjusted bymeans of a mechanical joint. The remaining gap openings and therequirement for sealing air which results from them can thus be matchedto the operating conditions and to the amount of sealing air availableat the respective point of use.

[0018] The heat protection element is advantageously held on thesupporting structure by means of a bolt. The bolt acts approximately inthe center of the heat protection element, in order to introduce thecontact force as centrally as possible into the heat protection element.The heat-resistant separating layer has a recess in the region in whichthe bolt of the associated heat protection element is attached to themetallic supporting structure. Further recesses and openings in theseparating layer, in particular in a gas turbine, are likewise providedwherever the supporting structure has channels for supplying sealing airinto the cavity formed by the heat protection element and the supportingstructure. Sealing air can thus flow into the cavity, thus making itpossible to prevent the hot active fluid from flowing behind the heatprotection elements and/or the separating layer.

[0019] The heat protection element can preferably also be mechanicallyheld against the metallic supporting structure by means of atongue-and-groove joint.

[0020] The object relating to a combustion area is achieved, accordingto the invention, by a combustion chamber forming a combustion area, inparticular a combustion chamber in a gas turbine, which is formed fromwall segments described above. In order to provide a heat-resistantlining for the combustion area, heat protection elements are fitted on ametallic supporting structure of the wall segment. The heat protectionelements are, for example, in the form of flat or curved polygons withstraight or curved edges, or of flat, regular polygons. They completelycover the metallic supporting structure which forms the outer wall ofthe combustion area, except for expansion gaps provided between the heatprotection elements. Hot fluid can penetrate into the expansion gapsonly as far as a heat-resistant separating layer on the wall segment,and cannot flow behind the heat protection elements. Mechanical holdersfor the heat protection elements, and the metallic supporting structure,are thus largely protected against being damaged by hot fluid.

[0021] The wall segment and a combustion area will be explained in moredetail with reference to the exemplary embodiments which are illustratedin the drawing. The following schematic illustrations are shown in thefigures:

[0022]FIG. 1 shows a wall segment with a separating layer composed of ametal grid with filled, honeycomb cells on a curved supportingstructure,

[0023]FIG. 2 shows an enlarged detail from FIG. 1,

[0024]FIG. 3 shows a wall segment with a separating layer composed of ametal felt on a supporting structure provided with webs,

[0025]FIG. 4 shows a wall segment with a thin coating in the form of aseparating layer applied to a supporting structure.

[0026]FIG. 1 shows a wall segment 1 of a gas turbine combustion chamberforming a combustion area 2, which is not illustrated in any moredetail. The wall segment 1 comprises a metallic supporting structure 3,to whose internal wall 5, facing the combustion area 2, a heat-resistantseparating layer 7 is applied. The heat-resistant separating layer 7comprises a metal grid, which is not shown in any more detail, withhoneycomb cells. The metal strips of the metal grid which form thehoneycomb cells have a height which corresponds to the thickness of theseparating layer 7. The honeycomb cells of the metal grid are filledwith a deformable filling material.

[0027] A ceramic heat protection element 9 is fitted on thecombustion-area side of the separating layer 7. The ceramic heatprotection element 9 is held on the metallic supporting structure 3 bymeans of a bolt 11. The bolt 11 is held in a hole 10 in the ceramic heatprotection element 9, and this hole runs essentially parallel to aperpendicular to a hot-gas side 21 of the heat protection element 9,through the region of the center of the heat protection element 9. Inconsequence, a contact force F produced by the bolt 11 is introducedessentially centrally into the heat protection element 9. One end of thebolt 11 projects through a hole 12 in the supporting structure 3. Thisend of the bolt 11 is closed off by a nut 13, which has an associatedspring 15. The nut 13 makes it possible to adjust the contact force Fapplied to the heat protection element 9 via the bolt 11. It is thusalso possible at the same time to adjust the penetration depth of theheat protection element 9 into the separating layer 7, and thus itsdeformation. The greater the contact force F with which the heatprotection element 9 is pressed onto the heat-resistant separating layer7, the deeper the heat protection element 9 penetrates into theseparating layer 7. FIG. 2 shows how the heat protection element 9deforms the separating layer 7, and partially penetrates into it, as aresult of the contact force F.

[0028] Channels 17 are provided in the metallic supporting structure 3,through which sealing air S can be applied to a cavity 19 formed by theheat protection element 9 and the supporting structure 3 with theseparating layer 7. For this purpose, the separating layer 7 is providedwith corresponding openings, which are not illustrated, at those pointson the supporting structure 3 where channels 17 are provided, throughwhich openings the sealing air S can enter the cavity 19. In the regionin which the bolt 11 is held against the metallic supporting structure3, the separating layer 7 has an opening, which is not shown in any moredetail, in which the bolt 11 is held.

[0029] During operation of the gas turbine, hot active fluid A isproduced in the combustion area 2 of the combustion chamber. The activefluid A is guided by the wall segment 1 on the hot-gas side 21 whichfaces the combustion area and is formed by the heat protection elements9. The heat protection elements 9 prevent direct contact between the hotactive fluid A and the metallic supporting structure 3. Expansion gaps22 to compensate for length changes of the heat protection elements 9are provided between adjacent heat protection elements 9 of a wallsegment 3, for thermal expansion. Hot active fluid A can penetrate intothese expansion gaps 22 as far as the separating layer 7. The deformablefilling material of the heat-resistant separating layer 7 preventsdirect contact between the active fluid A and the metallic supportingstructure 3, seals the cavity 19 against the ingress of hot active fluidA, and thus prevents any flow behind the heat protection elements 9. Theseparating layer 7 is slightly domed in the region of the expansion gap21 as a result of the longitudinal expansion of the heat protectionelements 9, and thus additionally seals the cavity 19 against theingress of active fluid A. In order to reinforce the barrier effect ofthe separating layer 7 and of the heat protection elements 9, sealingair S is applied to the cavity 19 through the channels 17. The sealingair S emerges into the expansion gaps 22 at those points which are notcompletely sealed against the hot active fluid A by the separating layer7, as is shown schematically in FIG. 2. The pressure drop from thecavity 19 to the combustion area produced by the sealing air S preventsactive fluid A from entering the cavity 19.

[0030] The different thermal expansion of the heat protection element 9and of the metallic supporting structure 3 can lead to relativemovements between the heat protection element 9 and the supportingstructure 3 when load changes occur in the gas turbine. However,relative movements can also occur as a result of pulsations in thecombustion area, caused by irregular combustion or resonances. Suchrelative movements which occur during operation can likewise becompensated for the partially elastically deformable separating layer 7.The introduction of increased forces into the heat protection element 9on the contact surfaces, for example as a result of a sudden pressurerise, can be reduced by the compression of the separating layer 7, andthe enlarged contact area resulting from this.

[0031]FIG. 3 shows a further embodiment of a wall segment 1 for a gasturbine combustion chamber which forms a combustion area 2 but is notshown in any more detail. The wall segment 1 comprises a metallicsupporting structure 23, a heat-resistant separating layer 25 and ametallic heat protection element 27. The metallic supporting structure 3has webs 29, which each form a contact surface for the heat protectionelement 27. The webs 29 are arranged such that the associated heatprotection element 27 rests on the webs 29 in the region of the edge ofits surface on the supporting-structure side. The heat protectionelement 27 thus acts like a cover closing the depression formed by thewebs 29 and by parts of the supporting structure 23. At least onechannel 31 for supplying sealing air S is provided between each two webs29. The metallic heat protection element 27 is held in a sprung manneragainst the metallic supporting structure 23 by means of a bolt 29(analogously to the bolt described in FIG. 1).

[0032] The separating layer 25 is in the form of a felt composed ofthin, heat-resistant metal wires, which are not shown in any moredetail, and lines the inner side of the supporting structure 23, facingthe combustion area 2. The separating layer 25 has openings in theregion of an opening 26 for the bolt 29 to pass through the supportingstructure 23, and in the region of the opening 32 of the channel 31. Thebolt 29 is held in the opening 26, while sealing air S can flow throughthe other opening, out of the channel 31 into the cavity 33 formed bythe heat protection element 27 and the supporting structure 23. The heatprotection element 27 deforms the separating layer 25 in the region ofthe webs 29. Gap openings which are formed between the contact surfacesof the heat protection element 27 and the web 29 but are not shown inany more detail are closed by the separating layer 25, or theircross-sectional area is reduced. This prevents the sealing air S fromemerging from the cavity 33 into the expansion gaps 35 formed betweentwo heat protection elements 27, or at least reduces such flow. It isthus impossible for hot active fluid A to penetrate as far as themetallic supporting structure 23 or to flow behind the heat protectionelements 27.

[0033]FIG. 4 shows a further embodiment of a wall segment 1. The wallsegment 1 comprises a metallic supporting structure 41 with a heatprotection element 47. The heat protection element 47 is linked to thesupporting structure 41 in a sprung manner by means of a bolt 49, in ananalogous manner to the bolt described in FIG. 1 on the inner side 43 ofthe supporting structure 41. A heat-resistant separating layer 45 isapplied to the supporting structure 41 between the side of thesupporting structure 41 facing the combustion area 2 and the side 51 ofthe heat protection element 47 facing away from the combustion area. Theheat-resistant separating layer is in the form of a thin, heat-resistantcoating 45 on the metallic supporting structure 41. The thin, deformablecoating 45 fills the entire area between the heat protection element 47and the supporting structure 41, so that irregularities of thesupporting structure 41 and/or of the heat protection element 47 causedby production effects or occurring during operation of the system arecompensated for. Furthermore, hot active fluid A thus cannot flow behindthe heat protection element 47. The active fluid A can penetrate as faras the heat-resistant coating 45 through the expansion gaps 22 formed byadjacent heat protection elements 47. The coating 45 prevents directcontact of the active fluid A with the metallic supporting structure 41.Relative movements of the heat protection element 47 and of thesupporting structure 41 can be compensated for by the elastic and/orplastic deformation of the coating 45. This avoids damage to the heatprotection element and/or to the supporting structure 41.

1. A wall segment (1) for a combustion area (2), to which a hot fluid(A) can be applied, having a metallic supporting structure (3) andhaving a heat protection element (9) which is mounted on the metallicsupporting structure (3), characterized in that the metallic supportingstructure (3) is provided at least in places with a thin, heat-resistantseparating layer (7), with the separating layer (7) being fitted betweenthe metallic supporting structure (3) and the heat protection element(9).
 2. A wall segment (1) for a combustion area (2), to which a hotfluid (A) can be applied, having a metallic supporting structure (3) andhaving a heat protection element (9) which is mounted on the metallicsupporting structure (3), characterized in that the metallic supportingstructure (3) is provided at least in places with a metallic,heat-resistant separating layer (7), with the separating layer (7) beingfitted between the metallic supporting structure (3) and the heatprotection element (9).
 3. The wall segment (1) as claimed in claim 1 or2, characterized in that the heat-resistant separating layer (7) can beelastically and/or plastically deformed by means of the heat protectionelement (9).
 4. The wall segment (1) as claimed in one of the precedingclaims, characterized in that the separating layer (3) has a layerthickness which is less than the height of the heat protection element.5. The wall segment (1) as claimed in one of the preceding claims,characterized in that the separating layer (3) has a layer thickness ofup to a few millimeters, in particular less than 1 mm.
 6. The wallsegment (1) as claimed in one of claims 1 to 5, characterized in thatthe heat-resistant separating layer (7) comprises a metal grid withhoneycomb cells.
 7. The wall segment (1) as claimed in claim 6,characterized in that the honeycomb cells of the heat-resistantseparating layer (7) are filled with a deformable filling material. 8.The wall segment (1) as claimed in one of claims 1 to 5, characterizedin that the heat-resistant separating layer (7) comprises a feltcomposed of metal wires.
 9. The wall segment (1) as claimed in one ofclaims 1 to 8, characterized in that the heat-resistant separating layer(7) is a thin coating on the metal supporting structure (3).
 10. Thewall segment (1) as claimed in one of claims 1 to 9, characterized inthat the heat-resistant separating layer (3) is scale-resistant at atemperature of more than 500° C., in particular up to approximately 800°C.
 11. The wall segment (1) as claimed in one of claims 1 to 10,characterized in that the heat protection element (9) is mechanicallyconnected to the metallic supporting structure (3).
 12. The wall segment(1) as claimed in claim 11, characterized in that the heat protectionelement (9) is connected to the metallic supporting structure (3) bymeans of a tongue-and-groove joint.
 13. The wall segment (1) as claimedin claim 11, characterized in that the heat protection element (9) isconnected to the metallic supporting structure (3) by means of a bolt(11).
 14. A combustion area (2) having a wall segment (1) as claimed inone of claims 1 to 13, characterized in that the wall segment (1) ispart of a combustion chamber of a gas turbine. Wall segment for acombustion area, and a combustion area The invention relates to a wallsegment (1) for a combustion area (2) to which a hot fluid (A) can beapplied. The wall segment (1) has a metallic supporting structure (3)and a heat protection element (9) mounted on it, with the metallicsupporting structure (3) being provided at least in places with a thinand/or metallic, heat-resistant separating layer (7). The separatinglayer (7) is fitted between the metallic supporting structure (3) andthe heat protection element (9).
 1. A wall segment (1) for a combustionarea (2), to which a hot fluid (A) can be applied, having a metallicsupporting structure (3) and having a heat protection element (9) whichis mounted on the metallic supporting structure (3), characterized inthat the metallic supporting structure (3) is provided at least inplaces with a metallic, heat-resistant separating layer (7), with theseparating layer (7) being fitted between the metallic supportingstructure (3) and the heat protection element (9).
 2. The wall segment(1) as claimed in claim 1, characterized in that the heat-resistantseparating layer (7) can be elastically and/or plastically deformed bymeans of the heat protection element (9).
 3. The wall segment (1) asclaimed in one of the preceding claims, characterized in that theseparating layer (3) has a layer thickness which is less than the heightof the heat protection element.
 4. The wall segment (1) as claimed inone of the preceding claims, characterized in that the separating layer(3) has a layer thickness of up to a few millimeters, in particular lessthan 1 mm.
 5. The wall segment (1) as claimed in one of claims 1 to 4,characterized in that the heat-resistant separating layer (7) comprisesa metal grid with honeycomb cells.
 6. The wall segment (1) as claimed inclaim 5, characterized in that the honeycomb cells of the heat-resistantseparating layer (7) are filled with a deformable filling material. 7.The wall segment (1) as claimed in one of claims 1 to 4, characterizedin that the heat-resistant separating layer (7) comprises a feltcomposed of metal wires.
 8. The wall segment (1) as claimed in one ofclaims 1 to 7, characterized in that the heat-resistant separating layer(7) is a thin coating on the metal supporting structure (3).
 9. The wallsegment (1) as claimed in one of claims 1 to 8, characterized in thatthe heat-resistant separating layer (3) is scale-resistant at atemperature of more than 500° C., in particular up to approximately 800°C.
 10. The wall segment (1) as claimed in one of claims 1 to 9,characterized in that the heat protection element (9) is mechanicallyconnected to the metallic supporting structure (3).
 11. The wall segment(1) as claimed in claim 10, characterized in that the heat protectionelement (9) is connected to the metallic supporting structure (3) bymeans of a tongue-and-groove joint.
 12. The wall segment (1) as claimedin claim 10, characterized in that the heat protection element (9) isconnected to the metallic supporting structure (3) by means of a bolt(11).
 13. A combustion area (2) having a wall segment (1) as claimed inone of claims 1 to 12, characterized in that the wall segment (1) ispart of a combustion chamber of a gas turbine.